How to sync your Gmail/Google Apps Contacts

I have tested this with iOS and Mac OS X 10.8

Go to where you would setup your contacts.  For instance in OS X you would open the contacts app and go to add account.

For iOS you would go to the mail, contacts, calendar section.

Click new for both.

Select Add CardDav Account.

Server: google.com
Username: username@gmail.com (or this can be your google apps account)
Password:  enter your password (if your using 2-factor authentication, you need to create an app password)
Description: Whatever you want

The Contacts App takes a few minutes to sync but the iOS app should be instant.

Source: Link

How to Configure a Fully Syncing Gmail Setup Thunderbird (Email, Contacts, Calendar)

First download Thunderbird -> Link

Install

Configure Gmail (Link)

Download Google Contacts -> Google Contacts

Click Tools -> Add-ons -> Click the "stary" thing beside the search box -> Click Install Add-on From File

Go Back in to the Add-ons and select Exetensions -> Select Options under Google Contacts

• Under General, Change Address Book backups to 1
• Under Advance, Change the working directory to somewhere in My Documents
• If your under Vista or Windows 7 there should be a Contacts folder in the user profile
• If your under XP, I would just create a new folder in My Documents
• Under Mapping, beside your account, select the drop down box and select  my contacts

Open your address book and right click the tool bar and click customize

Drag the reload icon up to the tool bar and select done, click reload

You should now see a folder called Google-xxxxxx

Copy any local Contacts to that folder by dragging and dropping to it

• If you are doing this on a second computer, you may end up with duplicates.  At some point, login to www.gmail.com and go to contacts.  Once in contacts select More-> Find & Merge Duplicates

Last thing is to make the Gmail the default option when creating a new contact

Close the Address book and go back to Thunderbird

Click Tools -> Options -> Advanced -> General -> Config Editor, Click that you'll be careful.

In the search box type ldap_2.servers

• What we are looking for are the .position -> type ldap_2.servers.*.position
• If you want to see all of the contact settings type  ldap_2.servers.
• Locate ldap_2.servers.history.position -> Double Click -> change value to 3
• Locate ldap_2.servers.pab.position -> Double Click -> change value to 2
• If this doesn't work, look through the whole list and see if there are other contact folders
• The values have to be greater than 3 and can't be duplicated

**This looks like it works in version 3, but not in 7.  I have not found a solution yet.

Source: Link

This was done on two computers, one with Windows 7 and one with Windows XP.

I will add the calendar part in the future.